Very-early-onset Inflammatory Bowel Disease in an Infant with a Partial RIPK1 Deletion.

The monogenic causes of very-early-onset inflammatory bowel disease (VEO-IBD) have been defined by genetic studies, which were usually related to primary immunodeficiencies. Receptor-interacting serine/threonine-protein kinase-1 (RIPK1) protein is an important signalling molecule in inflammation and cell death pathways. Its deficiency may lead to various clinical features linked to immunodeficiency and/or inflammation, including IBD. Here, we discuss an infant with malnutrition, VEO-IBD, recurrent infections and polyathritis who has a homozygous partial deletion in RIPK1 gene.

A Rare Contiguous Gene Deletion Leading to Trichothiodystrophy Type 4 and Glutaric Aciduria Type 3.

Introduction: Trichothiodystrophy type 4 and glutaric aciduria type 3 are rare autosomal recessive disorders caused by biallelic variants in the MPLKIP and SUGCT genes on chromosome 7p14, respectively. Trichothiodystrophy type 4 is characterized by neurologic and cutaneous abnormalities. Glutaric aciduria type 3 is a rare metabolic disorder with inconsistent phenotype and elevated urinary excretion of glutaric acid. Case Presentation: Here, we report on an infant presenting with hypotonia, failure to thrive, microcephaly, dysmorphic features, brittle hair, hypertransaminasemia, and recurrent lower respiratory tract infections. Microarray analysis revealed a homozygous microdeletion involving the MPLKIP and SUGCT genes, which are located close to each other. Conclusion: Copy number variations should be considered in patients with coexisting clinical expression of different genetic alterations. To the best of our knowledge, our patient is the second case with co-occurrence of trichothiodystrophy type 4 and glutaric aciduria type 3, resulting from a contiguous gene deletion.

EXTL3-Associated Immunoskeletal Dysplasia with Neurodevelopmental Abnormalities: A Lethal Phenotype.

Background: Immunoskeletal dysplasia with neurodevelopmental abnormalities (ISDNA) caused by Exostosin-Like Glycosyltransferase 3 (EXTL3) biallelic mutations is a very rare syndrome with only 16 cases reported in the literature. Skeletal dysplasia, neurodevelopmental delay, immunodeficiency, liver, and kidney cysts are the most common findings of this syndrome. Case Presentation: Here, we report on a patient who exhibited a lethal phenotype with clinical characteristics of this syndrome and had a homozygous pathogenic mutation in EXTL3 gene. Conclusions: ISDNA should be kept in mind in the differential diagnosis of patients presenting with neuro-immuno-skeletal dysplasia phenotype.

Novel sphingosine-1-phosphate lyase mutation causes multisystemic diseases: case report.

BACKGROUND: Sphingosine phosphate lyase insufficiency syndrome (SPLIS) caused by inactivating mutations in the human SGPL1 gene results in congenital nephrotic syndrome, adrenal insufficiency, ichthyosis, immunodeficiency, and a wide range of pathological neurological features. We present a novel mutation in the SGPL1 gene causing hypocalcemia, primary adrenal insufficiency (PAI), nephrotic syndrome, subclinical hypothyroidism, lymphopenia, ptosis, and pathologic neuroimaging findings. CASE: A Turkish male infant presented with bruising at 2 months of age and was diagnosed with hypocalcemia, PAI, and subclinical hypothyroidism. At the age of 15 months, he was admitted to the hospital with ptosis. Other systemic manifestations included persistent lymphopenia and nephrotic syndrome. Magnetic resonance imaging (MRI) of the brain and orbit demonstrated asymmetric contrast enhancement in the left cavernosal sinus, orbital apex, and thinning at the bilateral optic nerve. Whole exome sequencing (WES) revealed a homozygous c.1432C > G (p.Gln478Glu) variant in the SGPL1 gene (NM_003901.4), which has not previously been reported in the literature. CONCLUSIONS: Novel mutations in SGPL1 are still being identified. This case reminded us that SPLIS should not be considered for patients with nephrotic syndrome alone. Still, PAI may also include patients with neurological disorders, hypocalcemia, and pathological neuroimaging findings such as thinning at the bilateral optic nerve.